Action Language for UML (Alf)
Open Source Reference Implementation

Copyright © 2011-2020 Model Driven Solutions, Inc.

Alf is an action language for UML developed in response to the OMG Concrete Syntax for a UML Action Language Request for Proposals. The Alf specification document can be found at http://www.omg.org/spec/ALF. (See also http://solitaire.omg.org/issues/task-force/ALF11 for the list of issues addressed by the Alf 1.1 Revision Task Force.)

This implementation is based on the Alf 1.1 specification. It compiles Alf source text to the executable Foundational UML (fUML) subset of UML. The compilation can target either of two fUML execution engine implementations:

• The fUML Reference Implementation execution engine (see http://fuml.modeldriven.org), v1.3.0 (this version conforms to fUML 1.3).
• The fUML execution engine from the Moka framework for model execution in the Eclipse Papyrus tool (see http://wiki.eclipse.org/Papyrus/UserGuide/ModelExecution), v3.1.0.

The implementation handles the full Alf syntax at the Extended compliance level, as given in Annex C Consolidated LL Grammar of the Alf Specification.

Static semantic checking is directly based on validating the constraints defined in the abstract syntax of the Alf Specification. However, as errors were discovered in these definitions, or inconsistencies with corresponding feature descriptions were identified, these were corrected in the implementation. All such issues have either been corrected in the latest version of the specification or have been reported to the Alf Revision Task Force for correction in a future version.

The latest version of the implementation is available at http://alf.modeldriven.org.

Licensing

Model Driven Solutions, Inc., (formerly Data Access Technology, Inc.) is copyright owner of the source code for this implementation. For licensing terms, see the file LICENSING.txt.

Installation

The latest packaged distribution of the implementation is available in the dist directory.

Within this directory, the file alf.zip unzips into the installation directory for Alf. The installation directory includes Unix (BASH) shell scripts and DOS batch files for running Alf. By default, the Libraries subdirectory is expected to be in the same directory as the scripts. If you move it, set the environment variable ALF_LIB to its path.

Further Information

The following sections describe the project structure and build steps for the implementation. For further information on using it, see the wiki.

Projects

The base implementation source is organized into the following Eclipse projects. The build is currently tested on Eclipse 2020-06 (4.16).

• org.modeldriven.alf - This is the base project, including the Alf parser, static semantic checking and generic mapping to fUML. The generic mapping is not dependent on any specific UML metamodel or fUML implementation, but it must be extended with a specific UML metamodel implementation in order to generate actual UML model output.

• org.modeldriven.alf.fuml.impl - This project extends the base project to specialize the mapping to target the fUML Reference Implementation and to allow compiled Alf text to be executed. It does not depend on the fUML Reference Implementation project directly but, rather, uses an exported fuml.jar file.

• org.modeldriven.alf.eclipse - This project extends the base project to specialize the mapping to target the Eclipse UML2 metamodel implementation (v5.2.0 or later). It depends on Eclipse plugins and must be built in an Eclipse environment.

• org.modeldriven.alf.eclipse.moka - This project extends the org.modeldriven.alf.eclipse project to allow compiled Alf text to be executed using the fUML execution engine from the Moka framework for model execution in the Eclipse Papyrus modeling tool (specifically v3.1.0). It depends on Eclipse plugins and must be built in an Eclipse environment. (Note: This project was called org.modeldriven.alf.eclipse.papyrus in previous versions of the reference implementation.)

• org.modeldriven.alf.tests - This project provides automated tests.

Building

Maven project structure

The project structure under Maven allows building the regular Java modules and the Eclipse-based modules (using Tycho).

Master module build

• ./master/pom.xml - a module that provides standard configurations to be shared by all modules, including the root module.

Regular Java build

• ./pom.xml - the parent module for the regular Java modules
• ./org.modeldriven.alf - see Projects above.
• ./org.modeldriven.alf.fuml.impl - see Projects above.
• ./org.modeldriven.alf.tests - see Projects above.
• ./org.modeldriven.alf.bundle - produces a OSGi-bundle from org.modeldriven.alf
• ./org.modeldriven.alf.fuml.impl.bundle - produces a OSGi-bundle from org.modeldriven.alf.fuml.impl

Tycho build

• ./tycho-pom.xml - a convenience module that can be used for performing the Tycho (OSGi) aware part of the build. Equivalent to building ./tycho-parent/pom.xml
• ./tycho-parent/pom.xml - the parent module for the Tycho/Eclipse modules
• ./org.modeldriven.alf.eclipse - see Projects above.
• ./org.modeldriven.alf.eclipse.moka - see Projects above.

Steps

1. Master module build (required only once):

mvn clean install -f master

2. To perform the regular Java build, execute from the root directory:

mvn clean install

3. To perform the Tycho build, execute from the root directory:

mvn clean install -f tycho-pom.xml

Importing into Eclipse

Prerequisites

1. Eclipse JDT - Java development tools
2. Eclipse PDE - Plug-in development environment
3. Eclipse M2E - Maven Integration in Eclipse

By downloading the Eclipse SDK, you should have all those components.

Importing as Eclipse projects

That is the simplest way to import the codebase into Eclipse.

1. Import the root directory location using the "Existing Projects into Workspace" option, making sure to select the "Search for nested projects" option.
2. Configure the target platform preferences to use the alf-ri.target definition you just imported
3. You may be asked to install M2E extensions to support Tycho projects - this is recommended.

Importing as Maven modules

Alternately, you can import the code as Maven modules, which is recommended to obtain a configuration that is consistent with how the Maven build operates on the codebase.

1. Import the repository root directory and all its children artifacts as "Existing Maven projects" (note that will not include the alf.eclipse and alf.eclipse.moka projects, as they are not modules for the base Maven build). Note: If you see a build problem with the message "Duplicate bundle executions found. Please remove any explicitly defined bundle executions in your pom.xml.", make any non-content change to the POM file and save it, which should make the error go away.
2. Import the tycho-parent directory and all its children artifacts as "Existing Maven projects".
3. Configure the target platform preferences to use the alf-ri.target definition you just imported
4. You may be asked to install M2E extensions to support Tycho projects - this is recommended.